Training bench

ABSTRACT

A conventional training bench has a problem in that there is a risk of a user being hurt due to a backrest seat inclining more than necessary against the user&#39;s intention. A training bench  10  of the present invention mainly has a leg frame  11 , a back frame  12 , a movable frame  13 , a seat part  14 , a back seat  15 , an angle adjustment mechanism  16 , an operation part  17 , and a restriction part  18 . The angle adjustment mechanism  16  controls and causes the back frame  12  to transition between a fixed state and an angle adjustment state appropriately, so as to prevent the back seat  15  from inclining too much against the user&#39;s intention during training. The training bench  10  thus offers excellent safety.

TECHNICAL FIELD

The present invention relates to a training bench and particularly to atraining bench that allows a user sitting on a seat part to adjust aback seat to a desired angle with a simple operation and providesexcellent safety by preventing the back seat from inclining too muchagainst the user's intention.

BACKGROUND ART

The structure shown in FIG. 6 is known as the structure of aconventional training bench 100. FIG. 6 is a side view illustrating theconventional training bench 100.

As shown in FIG. 6, the training bench 100 mainly includes a mount frame101, a cross-bridging frame 102, a sitting seat 103 fixed to thecross-bridging frame 102, a backrest seat 104 turnably disposed at thecross-bridging frame 102, a main pillar 105 turnably disposed at theback surface of the backrest seat 104, an operation lever 106 disposedat the cross-bridging frame 102, and an angle adjustment mechanism 107operated by the operation lever 106.

The angle adjustment mechanism 107 mainly has a stopper portion 108 foradjustment of the length of the main pillar 105 and a wire 109 coupledto the operation lever 106. The stopper portion 108 has a stopper pin110 and a spring 111 that allows the stopper pin 110 to be inserted toand removed from the main pillar 105, and the wire 109 is coupled to thestopper pin 110.

In the training bench 100 thus structured, when a user sitting on thesitting seat 103 pulls the operation lever 106, the wire 109 contracts,pulling the stopper pin 110 out of the main pillar 105. Then, after thebackrest seat 104 is inclined to a desired inclination angle in thisstate, the operation lever 106 is returned to its original position,which inserts the stopper pin 110 back into the main pillar 105,securing the backrest seat 104 (see, for example, Patent Literature 1).

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Examined Utility Model Registration    Application Publication No. Hei 07-24121

SUMMARY OF INVENTION Technical Problem

As described above, a user of the training bench 100 can adjust thebackrest seat 104 to a desired inclination angle by operating theoperation lever 106 while remaining seated on the sitting seat 103.Thus, the user does not have to get out of the training bench 100 everytime they adjust the inclination angle of the backrest seat 104 and cancarry out the training smoothly.

However, the backrest seat 104 is adjusted with the stopper pin 110pulled out of the main pillar 105; thus, if the weight of the user isexerted on the backrest seat 104 more than necessary, the backrest seat104 may incline more than necessary against the user's intention. Insuch a case, the user may hurt themselves unexpectedly by, e.g.,striking the head against the backrest seat 104 that is inclined toomuch. There is therefore a security issue.

Also, to adjust the angle of the backrest seat 104, the user leans onthe backrest seat 104 and pushes the backrest seat 104 using, e.g.,their back while turning back on the main pillar 105. Then, the user hasto perform the angle adjustment of the backrest seat 104 while beingunable to see the positions of lock holes (not shown) on the main pillar105 into which the stopper pin 110 is to be inserted, and needs toperform minor adjustments of the angle of the backrest seat 104 untilthe stopper pin 110 is inserted into the lock hole near the desiredangle. Thus, there is an issue of poor handleability.

Also, if the stopper pin 110 is inserted into a different lock hole as aresult of the minor adjustments of the backrest seat 104, causing thebackrest seat 104 not to be at the inclination angle desired by theuser, the user has to operate the operation lever 106 and adjust theangle of the backrest seat 104 all over again. Thus, there is an issueof cumbersome operation. Also, in the structure in which the backrestseat 104 is fixed in position using the stopper pin 110, the lock holesneed to be spaced away from one another at certain intervals for reasonssuch as strength, which makes fine angle adjustments of the backrestseat 104 difficult. Thus, there is an issue of inconvenience to theuser.

The present invention has been made in view of the above circumstancesand provides a training bench that allows a user sitting on a seat partto adjust a back seat to a desired angle with a simple operation andprovides excellent safety by preventing the back seat from inclining toomuch against the user's intention.

Solution to Problem

A training bench of the present invention includes: a leg frame; a backframe that is supported by the leg frame; a movable frame that has afirst end portion turnably disposed relative to the back frame and asecond end portion slidably disposed relative to the leg frame; an angleadjustment mechanism that adjusts an inclination angle of the backframe; and an operation part that operates the angle adjustmentmechanism, in which the angle adjustment mechanism forms a fixed statein which turning operation of the movable frame relative to the backframe is stopped so that the back frame is positionally fixed and anangle adjustment state in which turning operation of the movable framerelative to the back frame is permitted to make the inclination angle ofthe back frame adjustable.

Also, in the training bench of the present invention, in conjunctionwith a single operation of the operation part performed for transitionfrom the fixed state to the angle adjustment state, the angle adjustmentmechanism causes the back frame to transition from the angle adjustmentstate back to the fixed state.

Also, in the training bench of the present invention, the angleadjustment mechanism has an angle adjustment gear that is turnablydisposed relative to the back frame, a first arm part that is disposedat the back frame and that engages with or separates from the angleadjustment gear, and a second arm part that is disposed at the backframe and that turns in conjunction with operation of the operation partto cause the first arm part to turn. The first end portion of themovable frame is fixed relative to a support shaft part to which theangle adjustment gear is fixed. In the fixed state, the first arm partis engaged with the angle adjustment gear to stop the support shaft partfrom performing turning operation relative to the back frame, and in theangle adjustment state, the first arm part separates from the angleadjustment gear to permit the support shaft part to perform the turningoperation relative to the back frame.

Also, in the training bench of the present invention, the angleadjustment mechanism further has a protrusion piece part that isdisposed at the first arm part and a guide groove that is formed in thesecond arm part and that guides the protrusion piece part to cause thefirst arm part to turn. The back frame transitions from the fixed stateto the angle adjustment state when the protrusion piece part movesinside the guide groove, and the back frame transitions from the angleadjustment state to the fixed state when the protrusion piece part comesout of the guide groove after moving inside the guide groove.

Also, in the training bench of the present invention, the angleadjustment mechanism further has a movable piece part that is disposedat the second arm part and that performs extension and contractionoperation when pressed by the protrusion piece part in one direction,and when the protrusion piece part presses the movable piece part in theone direction after coming out of the guide groove to cause the movablepiece part to contract, the protrusion piece part returns back into theguide groove in conjunction with the turning operation of the second armpart.

Also, in the training bench of the present invention, a slide link partthat slides relative to the leg frame is disposed at the second endportion of the movable frame, and a restriction part is disposed at theslide link part, the restriction part extending toward the back frame torestrict an inclination range of the back frame.

Effects of the Invention

In the training bench of the present invention, the first end portion ofthe movable frame is turnably disposed relative to the back frame, whilethe second end portion of the movable frame is slidably disposedrelative to the leg frame. Then, the angle adjustment mechanism controlsthe turning operation of the movable frame and the back frame, and theuser can adjust the angle of the back frame during training by operatingthe operation part. The convenience is thus improved.

In the training bench of the present invention, in conjunction with anoperation of the operation part which causes the back frame totransition from the fixed state to the angle adjustment state, the angleadjustment mechanism causes the back frame to transition from the angleadjustment state back to the fixed state. This structure prevents theback frame from inclining too much against the user's intention, so thatthe user can adjust the angle of the back frame safely.

In the training bench of the present invention, the angle of the backframe can be adjusted by turning, relative to the back frame, of thesupport shaft part to which the angle adjustment gear and the first endportion of the movable frame are fixed. This structure enables angleadjustment of the back frame for each span of the tooth profiles of theangle adjustment gear, allowing fine angle adjustments of the back frameaccording to the user's training menu or the like. The convenience isthus improved.

In the training bench of the present invention, the protrusion piecepart is formed at the first arm part, and the guide groove is formed inthe second arm part to guide the protrusion piece part. When theprotrusion piece part comes out of the guide groove after moving in theguide groove, the first arm part in engagement with the angle adjustmentgear separates from the angle adjustment gear and then re-engages theangle adjustment gear in a single operation. This structure of thetraining bench allows the back frame to return to the fixed state in theend within a single operation, irrespective of the intention of theuser, and thus prevents the back frame from inclining too much, enablingthe user to use the training bench safely.

Also, in the training bench of the present invention, the movable piecepart that repeats extension and contraction operation in one directionis disposed at the second arm part. The extension and contractionoperation of the movable piece part performed in the process of thetransition from the angle adjustment state to the fixed state causes theprotrusion piece part to return into the guide groove, allowing theangle adjustment of the back frame to be repeated consecutively.

Also, in the training bench of the present invention, the restrictionpart is disposed at the movable frame to restrict the inclination rangeof the back frame. This structure ensures that even if any of thecomponents constituting the angle adjustment mechanism breaks, therestriction part restricts the inclination range of the back frame toprevent the user from, for example, being hurt during training.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are a perspective view and a side view, respectively,illustrating a training bench as an embodiment of the presentembodiment.

FIG. 2 is a perspective view illustrating the training bench as anembodiment of the present invention.

FIGS. 3A and 3B are a perspective view and an exploded perspective view,respectively, illustrating an angle adjustment mechanism in the trainingbench as an embodiment of the present invention.

FIGS. 4A and 4B are each a side view illustrating the operation of theangle adjustment mechanism in the training bench as an embodiment of thepresent invention.

FIGS. 5A and 5B are each a side view illustrating the operation of theangle adjustment mechanism in the training bench as an embodiment of thepresent invention.

FIG. 6 is a side view illustrating a conventional training bench.

DESCRIPTION OF EMBODIMENTS

Hereinbelow, a training bench 10 according to an embodiment of thepresent invention is described in detail based on the drawings. Notethat throughout the description of the present embodiment, the samemembers are basically denoted by the same reference numerals to avoidrepetitive description. The up-down direction represents the heightdirection of the training bench 10, the left-right direction representsthe width direction of the training bench 10, and the front-reardirection represents the depth direction of the training bench 10.

FIG. 1A is a perspective view illustrating the training bench 10 of thepresent embodiment. FIG. 1B is a side view illustrating the trainingbench 10 of the present embodiment. FIG. 2 is a perspective viewillustrating a back frame 12 and an angle adjustment mechanism 16 of thetraining bench 10 of the present embodiment. FIG. 3A is a perspectiveview illustrating the angle adjustment mechanism 16 of the trainingbench 10 of the present embodiment. FIG. 3B is an exploded perspectiveview illustrating the angle adjustment mechanism 16 of the trainingbench 10 of the present embodiment.

As shown in FIGS. 1A and 1B, the training bench 10 mainly includes a legframe 11, the back frame 12 supported by the leg frame 11, a movableframe 13 disposed between the leg frame 11 and the back frame 12, a seatpart 14 supported by the leg frame 11, a back seat 15 supported by theback frame 12, the angle adjustment mechanism 16 disposed at the backframe 12, an operation part 17 that operates the angle adjustmentmechanism 16, and a restriction part 18 that restricts the inclinationrange of the back frame 12. A user uses the training bench 10 when doingweight training or the like, and during use, adjusts the angle of theback seat 15 relative to the seat part 14 according to, e.g., thetraining menu or the part of the body to work on.

The leg frame 11 is a frame for the training bench 10 to stand on afloor surface of a training room or the like and is formed from amaterial with desired rigidity, such as, for example, an iron materialor an aluminum material. The leg frame 11 mainly has two main pillarparts 11A, 11B and two leg parts 11C, 11D disposed at the lower ends ofthe main pillar parts 11B, 11A, respectively. Since their upper endportions are turnably linked, the main pillar parts 11A, 11B can becollapsed for storage when the training bench 10 is not used.

The back frame 12 is turnably linked to a link shaft part 24 of the legframe 11 (see FIG. 2) and has the back seat 15 attached to its frontsurface side. During training, for example, a user does weight trainingwhile leaning on the back seat 15; thus, like the leg frame 11, the backframe 12 is formed from a material with desired rigidity.

The movable frame 13 supports the back frame 12 from below and is formedfrom a material with desired rigidity like the leg frame 11. An upperend portion of the movable frame 13 is fixed to a support shaft part 22(see FIG. 2) that is turnably disposed relative to the back frame 12, sothat the movable frame 13 turns relative to the back frame 12 integrallywith the support shaft part 22. A lower end portion of the movable frame13 is slidably disposed at the main pillar part 11A of the leg frame 11.

Specifically, the movable frame 13 mainly has a main pillar part 13Adisposed between the leg frame 11 and the back frame 12 and a slide linkpart 13B that is disposed at the main pillar part 11A of the leg frame11 and moves guided by the main pillar part 11A.

The slide link part 13B has a publicly-known roller structure (notshown) inside and moves along the main pillar part 11A when the rollerstructure slides on the surface of the main pillar part 11A. Asdescribed above, the upper end portion of the main pillar part 13A turnsrelative to the back frame 12 integrally with the support shaft part 22,and the slide link part 13B moves along the main pillar part 11A inconjunction with this turning, allowing adjustment of the inclinationangle of the back frame 12. This structure allows the back frame 12 tobe moved from an upright state which is substantially perpendicular tothe mount surface to a substantially horizontal, recumbent state.

The restriction part 18 is a member that restricts the lower limitposition of the inclination range of the back frame 12 and moves alongthe main pillar part 11A integrally with the slide link part 13B. Therestriction part 18 is fixed to the upper surface side of the slide linkpart 13B and extends towards the back seat 15. The back frame 12 abutsthe tip end of the restriction part 18 when the back frame 12 comes to astate of being substantially flat with respect to the seat part 14 toprevent the back frame 12 and the back seat 15 from inclining further.

Even if one of components constituting the angle adjustment mechanism 16breaks to cause the back frame 12 to incline abruptly, the slide linkpart 13B does not come out of the main pillar part 11A. Even in theabove state where a component in the training bench 10 is broken, themechanical structure in which the back frame 12 abuts the tip end of therestriction part 18 prevents the back frame 12 and the back seat 15 frominclining further than the flat state, ensuring the safety for the user.

The seat part 14 mainly has a sitting seat 14A on which a user sits andsupport frames 14B, 14C that support the sitting seat 14A from below. Asshown, a first end portion of the support frame 14B is fixed to the mainpillar part 11B of the leg frame 11, and a first end portion of thesupport frame 14C is turnably attached to the back frame 12. The supportframe 14B itself has a publicly-known extension and contractionmechanism, so that the angle and height of the seat part 14 can beadjusted.

The back seat 15 is formed mainly of a cushion part on which a userleans and is fixed to the back frame 12, so that the back seat 15 turnsrelative to the leg frame 11 integrally with the back frame 12. The backseat 15 is adjusted to an inclination angle desired by the user when theuser operates the operation part 17 and inclines the back frame 12 viathe angle adjustment mechanism 16 and the like.

The operation part 17 is an operation lever substantially in the shapeof the letter U and has a pair of handle portions 17A disposed near theleft and right edge portions of the back seat 15, respectively. As willbe detailed later, part of the operation part 17 is fixed to a secondarm part 33 (see FIG. 3A) of the angle adjustment mechanism 16 at theback side of the back seat 15. When a user performs, for example,operation of pulling the operation part 17 frontward, the second armpart 33 turns, causing a first arm part 32 and an angle adjustment gear31 to transition from an engaged state to a separate state. Then, theangle of the back frame 12 can be adjusted.

As shown in FIG. 2, the back frame 12 mainly has two main pillar parts12A, 12B to which the back seat 15 is fixed and two bridge parts 12C,12D bridging the main pillar parts 12A, 12B in the width direction.Between the bridge parts 12C, 12D, three support shaft parts 21, 22, 23supporting the angle adjustment mechanism 16 are disposed, bridging linkplates 41 fixed to the main pillar parts 12A, 12B. The back frame 12 isturnably supported by the link shaft part 24 of the leg frame 11 and isadjusted to an inclination angle desired by the user by turning in thefront-rear direction of the training bench 10 with the link shaft part24 serving as a rotational pivot point.

The main pillar parts 12A, 12B are disposed near the left and right edgeportions of the back seat 15 to extend in the longitudinal direction,supporting the back seat 15 from its back surface side. The bridge parts12C, 12D are disposed near both end portions of the main pillar parts12A, 12B in the height direction, respectively, and are fixed by weldingto the main pillar parts 12A, 12B, so that desired rigidity and strengthof the back frame 12 is achieved.

As shown, the support shaft parts 21, 22, 23 are disposed substantiallyat the center portions of the main pillar parts 12A, 12B in the heightdirection. The support shaft parts 21, 22, 23 are disposed to bridge thepair of link plates 41 fixed by welding to the main pillar parts 12A,12B.

As shown also in FIG. 3B, the support shaft part 21 is bolted at itsboth end portions and is therefore fixed and does not turn relative tothe link plates 41. The support shaft part 22 has an elongate bolt 22Aand a hollow cylindrical shaft 22B, the elongate bolt 22A being fixedrelative to the link plates 41. The hollow cylindrical shaft 22B isrotatably disposed between the link plates 41 with the elongate bolt 22Abeing inserted therein, so that the support shaft part 22 is turnablerelative to the back frame 12. The support shaft part 23 has an elongatebolt 23A and a hollow cylindrical shaft 23B, the elongate bolt 23A beingfixed relative to the link plates 41. The hollow cylindrical shaft 23Bis rotatably disposed between the link plates 41 with the elongate bolt23A being inserted therein, so that the support shaft part 23 isturnable relative to the back frame 12.

In this structure, the support shaft part 21 is fixed relative to thelink plates 41, while the support shaft parts 22, 23 turn relative tothe link plates 41 via the hollow cylindrical shafts 22B, 23B. As willbe detailed later, when the angle adjustment gear 31 (see FIG. 3A) andthe first arm part 32 (see FIG. 3A) are in an engaged state, the supportshaft part 22 is fixed to the back frame 12 via the first arm part 32,and consequently, the movable frame 13 is also fixed relative to theback frame 12. When the angle adjustment gear 31 and the first arm part32 are in a separate state, the support shaft part 22 turns relative tothe back frame 12, and consequently the movable frame 13 also turnsrelative to the back frame 12. Note that the first arm part 32 isturnably supported by the support shaft part 21, the angle adjustmentgear 31 is fixed to the support shaft part 22, and the second arm part33 (see FIG. 3A) is fixed to the support shaft part 23.

The operation part 17 is fixed relative to the second arm part 33, andthe pair of handle portions 17A are disposed at heights substantiallyone third of the main pillar parts 12A, 12B in the height direction.With this structure, when a user sitting on the seat part 14 (see FIG.1A) and leaning on the back seat 15 stretches their both hands to theback side, they have easy access to grip and operate the pair of handleportions 17A. In this state, the user pulls the handle portions 17A ofthe operation part 17 frontward to bring the first arm part 32 and theangle adjustment gear 31 to a separate state and then pushes the backseat 15 rearward with their back, and as a result, the movable frame 13moves, allowing adjustment of the inclination angle of the back frame12.

As shown in FIGS. 3A and 3B, the angle adjustment mechanism 16 mainlyhas the angle adjustment gear 31 fixed to the support shaft part 22, thefirst arm part 32 that forms an engage state or a separate state withthe angle adjustment gear 31 with the support shaft part 21 serving as arotational pivot point, the second arm part 33 that turns together withthe support shaft part 23 to control the turning operation of the firstarm part 32, a first elastic part 34 that biases the first arm part 32toward the angle adjustment gear 31, a second elastic part 35 thatbiases the second arm part 33 toward the first arm part 32, a spiralspring 37 disposed at the support shaft part 22, protrusion piece parts38 fixed to the left and right side surfaces of the first arm part 32,guide grooves 39 formed in the second arm part 33, movable piece parts40 disposed at the second arm part 33, and third elastic parts 36 (seeFIG. 4A) that allow the movable piece parts 40 to move in one direction.For the convenience of illustration, the third elastic parts 36 are notshown.

The angle adjustment gear 31 is substantially fan-shaped and is formedfrom a material with desired rigidity, such as, for example, an ironmaterial or an aluminum material. In the arc region of the angleadjustment gear 31, a plurality of tooth profiles 31A are formed,arranged at certain intervals. The angle adjustment gear 31 is fixed bywelding to a substantially center area of the support shaft part 22. Theangle adjustment gear 31 does not perform turning operation solely, butperforms turning operation integrally with the support shaft part 22relative to the back frame 12.

The first arm part 32 is formed from, for example, the same material asthe angle adjustment gear 31 and is disposed such that at least partthereof faces the plurality of tooth profiles 31A in the arc region ofthe angle adjustment gear 31. A first end portion 32A of the first armpart 32 is pivotally and turnably supported by the support shaft part21. A second end portion 32B of the first arm part 32 has a plurality oftooth profiles 32C formed and arranged at certain intervals in a regionopposing the arc region of the angle adjustment gear 31, the toothprofiles 32C having substantially the same shapes as the tooth profiles31A. The region of the first arm part 32 where the tooth profiles 32Care formed is arc-shaped having substantially the same radius ofcurvature as the region of the angle adjustment gear 31 where the toothprofiles 31A are formed.

With this structure, the tooth profiles 32C of the first arm part 32 andthe tooth profiles 31A of the angle adjustment gear 31 engage with eachother, and when the first arm part 32 and the angle adjustment gear 31are in the engaged state, the support shaft part 22 is fixed relative tothe back frame 12 and stops turning. As a result, the movable frame 13fixed to the support shaft part 22 is also in a fixed state relative tothe back frame 12 and supporting the back frame 12 from behind. In otherwords, when the first arm part 32 and the angle adjustment gear 31 arein the engaged state, the inclination angle of the back frame 12 cannotbe adjusted, and the back frame 12 is in a fixed state where the backframe 12 is positionally fixed.

The pair of protrusion piece parts 38 are disposed on the respectiveside surfaces of the second end portion 32B of the first arm part 32.Each of the protrusion piece parts 38 is, for example, a columnarbar-shaped body made of the same material as the first arm part 32. Thefirst elastic part 34 is, for example, a coil spring and has a first endportion fixed to the support shaft part 21 and a second end portionfixed to the first arm part 32, so that the first arm part 32 is biasedby the first elastic part 34 toward the angle adjustment gear 31.

The second arm part 33 is formed from, for example, the same material asthe angle adjustment gear 31 and is disposed below the angle adjustmentgear 31 and the first arm part 32. A first end portion 33A of the secondarm part 33 is fixed by welding to a substantially center area of thesupport shaft part 23. The second arm part 33 does not perform turningoperation solely, but performs turning operation integrally with thesupport shaft part 23 relative to the back frame 12. The second arm part33 is a box-shaped body having a hollow portion inside, and in theengaged state described above, accommodates part of the angle adjustmentgear 31 and the first arm part 32 in the hollow portion and supportsthese members from below.

The pair of guide grooves 39 are formed at a second end portion 33B ofthe second arm part 33 to engage with the protrusion piece parts 38 ofthe first arm part 32 and guide the protrusion piece parts 38 inconjunction with the movement of the protrusion piece parts 38. As willbe detailed later, the movable piece parts 40 capable of extension andcontraction operation in one direction are formed on side surfaces ofthe second arm part 33, near the guide grooves 39. For example, thethird elastic part 36 (see FIG. 4A) is disposed at each movable piecepart 40. The extension and contraction operation of the third elasticpart 36 will be described later using FIGS. 4A to 5B.

The second elastic part 35 is, for example, a coil spring and has afirst end portion fixed to the support shaft part 21 and a second endportion fixed to the second arm part 33, so that the second arm part 33is biased by the second elastic part 35 toward the angle adjustment gear31 and the first arm part 32.

The spiral spring 37 is a member for biasing the back frame 12 frontwardand has a first end 37A which is a spiral start point fixed to thesupport shaft part 22 and a second end 37B which is a spiral end pointfixed to the support shaft part 21. With this structure, when thesupport shaft part 22 turns to cause the back frame 12 to inclinerearward, the spiral spring 37 wraps around the support shaft part 22 ina direction to tighten the support shaft part 22, biasing the back frame12 frontward.

The first arm part 32 is pivotally and turnably supported by the supportshaft part 21 as described above, but is unlikely to be displaced in theleft-right direction due to a structure such that the first arm part 32is disposed inside a recessed portion 21B at a substantially center areaof the support shaft part 21. Further, the second arm part 33 is fixedby welding to the support shaft part 23 and is thereby fixed inposition, while the first arm part 32 turns guided inside the second armpart 33. This structure makes it difficult for the first arm part 32 tobe displaced from the recessed portion 21B of the support shaft part 21.

Next, FIGS. 4A to 5B are side views illustrating how the angleadjustment mechanism 16 of the training bench 10 of the presentembodiment operates, FIGS. 4A, 5A, and 5B showing the first arm part 32and the angle adjustment gear 31 in the engaged state and FIG. 4Bshowing the first arm part 32 and the angle adjustment gear 31 in theseparate state. Note that FIGS. 4A to 5B do not show some of thecomponents constituting the angle adjustment mechanism 16 for theconvenience of illustration.

First, FIG. 4A shows a state before a user operates the operation part17, in which state the second arm part 33 supports the angle adjustmentgear 31 and the first arm part 32 from below with the first arm part 32and the angle adjustment gear 31 being in the engaged state. In thisstate, the second arm part 33 is biased by the second elastic part 35and is in a state of being closest to the first arm part 32. As aresult, the protrusion piece parts 38 of the first arm part 32 abut thebottom surfaces of the guide grooves 39 of the second arm part 33, sothat the first arm part 32 is in an unturnable state. The above engagedstate is supported by the first arm part 32 being pressed toward theangle adjustment gear 31. Note that the movable piece parts 40 are in amost extended state, without abutting and being pressed by theprotrusion piece parts 38.

As shown, the third elastic part 36 is, for example, a coil spring andhas a first end portion fixed to the movable piece part 40 and a secondend portion fixed to the second arm part 33. With this structure, themovable piece parts 40 perform extension and contraction operation whenpressed by the protrusion piece parts 38 in a direction to contract thethird elastic parts 36 (hereinafter referred to as “one direction”).When pressed by the protrusion piece parts 38 in directions other thanthe one direction (hereinafter referred to as “other directions”), themovable piece parts 40 do not perform the extension and contractionoperation and guide the protrusion piece parts 38 along their outerperimeters.

Next, as shown in FIG. 4B, when the user performs operation of pullingthe handle portions 17A of the operation part 17 frontward as indicatedby an arrow 42, the second arm part 33 turns, causing the first arm part32 to separate from the angle adjustment gear 31. Specifically, asindicated by an arrow 43, the second arm part 33 turns integrally withthe support shaft part 23 in conjunction with the movement of theoperation part 17 to move in a direction away from the angle adjustmentgear 31. As a result, the protrusion piece parts 38 move guided by theguide grooves 39 and the movable piece parts 40, so that the first armpart 32 turns in a direction indicated by an arrow 44. The first armpart 32 and the angle adjustment gear 31 thus transition from theengaged state to the separate state.

When the first arm part 32 and the angle adjustment gear 31 separatefrom each other as described above, the support shaft part 22 is now ina state of being turnable relative to the back frame 12, and theinclination angle of the back frame 12 can be adjusted when the userpushes the back seat 15 rearward with their back. In other words, theback frame 12 is in an angle adjustment state. Note that the movablepiece parts 40 are not pressed by the protrusion piece parts 38 and aretherefore in a most extended state.

Next, as shown in FIG. 5A, when the user continues the operation ofpulling the handle portions 17A of the operation part 17 frontward asindicated by an arrow 45 from the state shown in FIG. 4B to cause thesecond arm part 33 to turn even further, the first arm part 32 isreleased from the second arm part 33 and returns to the position shownin FIG. 4A, so that the first arm part 32 and the angle adjustment gear31 are in the engaged state. Specifically, the second arm part 33 turnsfurther in the direction indicated by an arrow 46 in conjunction withthe movement of the operation part 17, and consequently, the protrusionpiece parts 38 come out of the guide grooves 39. In other words, whenthe amount of turning of the operation part 17 exceeds the amount ofmovement of the protrusion piece parts 38 inside the guide grooves 39,the protrusion piece parts 38 are released from the state of being inconjunction via the guide grooves 39. Then, as indicated by an arrow 47,the first arm part 32 is biased by the first elastic part 34 (see FIG.3A) and returns to the state of being engaged with the angle adjustmentgear 31.

As described above, when the first arm part 32 and the angle adjustmentgear 31 are in engagement with each other, the support shaft part 22 isfixed to the back frame 12 and is in an unturnable state. In thisengaged state, the back frame 12 does not turn even if the user pushesthe back seat 15 rearward with their back, and the back frame 12 is thusin a fixed state.

In this state, as shown, the protrusion piece parts 38 out of the guidegrooves 39 move to the tip end portions of the movable piece parts 40and press the movable piece parts 40 in the one direction; thus, themovable piece parts 40 are in a slightly contracted state. Note that, asmentioned earlier, FIG. 5A shows a state where the user has pulled thehandle portions 17A of the operation part 17 frontward as far as it canget, and the second arm part 33 too has turned to a position farthestfrom the angle adjustment gear 31.

Next, as shown in FIG. 5B, as indicated by an arrow 48 when the userperforms operation of returning the handle portions 17A of the operationpart 17 rearward from the state shown in FIG. 5A, the second arm part 33turns in the direction indicated by an arrow 49, while the first armpart 32 and the angle adjustment gear 31 stay in the engaged state.

Specifically, when the second arm part 33 turns in the directionindicated by the arrow 49 in conjunction with the movement of theoperation part 17, the protrusion piece parts 38 further press themovable piece parts 40 in the one direction, causing the movable pieceparts 40 to contract. As a result, the protrusion piece parts 38 returnback into the guide grooves 39 which have returned integrally with thesecond arm part 33. Note that the operation part 17 is biased in thedirection indicated by an arrow 48 by an elastic part (not shown) suchas a coil spring, and the handle portions 17A return to the positionshown in FIG. 4A when the user releases the handle portions 17A.

After the handle portions 17A of the operation part 17 return to thepre-operation state shown in FIG. 4A, the protrusion piece parts 38 alsoreturn to the positions abutting the bottom surfaces of the guidegrooves 39, and the members constituting the angle adjustment mechanism16 return to the pre-operation state shown in FIG. 4A. As thusdescribed, the operation from FIGS. 4A to 5B is repeated at the angleadjustment mechanism 16 when the user operates the operation part 17once.

In the present embodiment, as described above, during a single operationof the user pulling the handle portions 17A of the operation part 17frontward for adjustment of the angle of the back frame 12, the firstarm part 32 and the angle adjustment gear 31 transition from the engagedstate shown in FIG. 4A to the separate state shown in FIG. 4B and thenreturns to the engaged state shown in FIG. 5A.

This structure prevents the back frame 12 from inclining too muchagainst the user's intention because the back frame 12 transitions fromthe angle adjustment state to the fixed state using a mechanicalmechanism not dependent on the user's intention. Specifically, the angleadjustment state lasts approximately one second although it depends onthe speed at which the user operates the operation part 17, and for thisreason, the back frame 12 is prevented from inclining too much againstthe user's intention during that state. As a result, although the userusually adjusts the angle of the back seat 15 without looking at theangle adjustment mechanism 16, the user is prevented from hurtingthemselves unexpectedly during that operation. Thus, the training bench10 offers excellent safety.

Further, in the training bench 10, the angle of the back seat 15 can beadjusted within substantially 90° from the substantially upright stateto the substantially flat state relative to the seat part 14. The angleadjustment mechanism 16 allows angle adjustment for each span of thetooth profiles 31A, 32C, making possible fine adjustments in, forexample, 16 stages or the like within the above substantially 90°. As aresult, the user can easily adjust the back seat 15 to a desired angleaccording to the training menu, and therefore the convenience isimproved.

Depending on the amount of turning of the back seat 15, the toothprofiles 31A, 32C may not mesh with each other perfectly at thetransition from the non-engaged state to the engaged state. However, thetooth profiles 31A, 32C come into the engaged state immediately becausethe tooth profiles 31A, 32C have a short span. As a result, the amountby which the back seat 15 slides rearward against the user's intentionis small, and therefore the training bench 10 offers excellent safety.Further, unlike a locking structure using a lock pin, the tooth profiles31A, 32C always come to engage with each other. Thus, the user is freedfrom the subtle angle adjustment for aligning the lock pin with the lockhole, which is required by the conventional structure, and therefore,the handleability is improved.

In the present embodiment described above, the back frame 12 isprevented from inclining too much because the mechanical mechanism ofthe angle adjustment mechanism 16 forces the first arm part 32 and theangle adjustment gear 31 to return from the separate state to theengaged state in a single operation of pulling the operation part 17frontward for adjustment of the angle of the back frame 12. However, thepresent invention is not limited to this case. For example, an operationrestriction mechanism (not shown) may be disposed near the operationpart 17 so that the amount of turning of the operation part 17 may besmaller than the amount of movement of the protrusion piece parts 38inside the guide grooves 39. In this case, when the user keeps the statewhere the operation part 17 is pulled frontward, the first arm part 32and the angle adjustment gear 31 stay in the separate state. Then, whenthe movable frame 13 turns relative to the back frame 12 with the backframe 12 staying in the angle adjustment state, the user can freelyadjust the angle of the back frame 12. In other words, the trainingbench 10 may be provided with the operation restriction mechanism andused to switch between a mode where the first arm part 32 and the angleadjustment gear 31 are forced to return from the separate state to theengaged state and a mode where the separate state is maintained. Variousother modifications can also be made without departing from the gist ofthe present invention.

REFERENCE SIGNS LIST

-   10 training bench-   11 leg frame-   12 back frame-   13 movable frame-   14 seat part-   15 back seat-   16 angle adjustment mechanism-   17 operation part-   18 restriction part-   21, 22, 23 support shaft part-   31 angle adjustment gear-   32 first arm part-   33 second arm part-   34 first elastic part-   35 second elastic part-   36 third elastic part-   38 protrusion piece part-   39 guide groove-   40 movable piece part

1. A training bench comprising: a leg frame; a back frame that issupported by the leg frame; a movable frame that has a first end portionturnably disposed relative to the back frame and a second end portionslidably disposed relative to the leg frame; an angle adjustmentmechanism that adjusts an inclination angle of the back frame; and anoperation part that operates the angle adjustment mechanism, wherein theangle adjustment mechanism forms a fixed state in which turningoperation of the movable frame relative to the back frame is stopped sothat the back frame is positionally fixed and an angle adjustment statein which turning operation of the movable frame relative to the backframe is permitted to make the inclination angle of the back frameadjustable.
 2. The training bench according to claim 1, wherein inconjunction with a single operation of the operation part performed fortransition from the fixed state to the angle adjustment state, the angleadjustment mechanism causes the back frame to transition from the angleadjustment state back to the fixed state.
 3. The training benchaccording to claim 2, wherein the angle adjustment mechanism has anangle adjustment gear that is turnably disposed relative to the backframe, a first arm part that is disposed at the back frame and thatengages with or separates from the angle adjustment gear, and a secondarm part that is disposed at the back frame and that turns inconjunction with operation of the operation part to cause the first armpart to turn, the first end portion of the movable frame is fixedrelative to a support shaft part to which the angle adjustment gear isfixed, in the fixed state, the first arm part is engaged with the angleadjustment gear to stop the support shaft part from performing turningoperation relative to the back frame, and in the angle adjustment state,the first arm part separates from the angle adjustment gear to permitthe support shaft part to perform the turning operation relative to theback frame.
 4. The training bench according to claim 3, wherein theangle adjustment mechanism further has a protrusion piece part that isdisposed at the first arm part and a guide groove that is formed in thesecond arm part and that guides the protrusion piece part to cause thefirst arm part to turn, the back frame transitions from the fixed stateto the angle adjustment state when the protrusion piece part movesinside the guide groove, and the back frame transitions from the angleadjustment state to the fixed state when the protrusion piece part comesout of the guide groove after moving inside the guide groove.
 5. Thetraining bench according to claim 4, wherein the angle adjustmentmechanism further has a movable piece part that is disposed at thesecond arm part and that performs extension and contraction operationwhen pressed by the protrusion piece part in one direction, and when theprotrusion piece part presses the movable piece part in the onedirection after coming out of the guide groove to cause the movablepiece part to contract, the protrusion piece part returns back into theguide groove in conjunction with the turning operation of the second armpart.
 6. The training bench according to claim 1, wherein a slide linkpart that slides relative to the leg frame is disposed at the second endportion of the movable frame, and a restriction part is disposed at theslide link part, the restriction part extending toward the back frame torestrict an inclination range of the back frame.
 7. The training benchaccording to claim 2, wherein a slide link part that slides relative tothe leg frame is disposed at the second end portion of the movableframe, and a restriction part is disposed at the slide link part, therestriction part extending toward the back frame to restrict aninclination range of the back frame.
 8. The training bench according toclaim 3, wherein a slide link part that slides relative to the leg frameis disposed at the second end portion of the movable frame, and arestriction part is disposed at the slide link part, the restrictionpart extending toward the back frame to restrict an inclination range ofthe back frame.
 9. The training bench according to claim 4, wherein aslide link part that slides relative to the leg frame is disposed at thesecond end portion of the movable frame, and a restriction part isdisposed at the slide link part, the restriction part extending towardthe back frame to restrict an inclination range of the back frame. 10.The training bench according to claim 5, wherein a slide link part thatslides relative to the leg frame is disposed at the second end portionof the movable frame, and a restriction part is disposed at the slidelink part, the restriction part extending toward the back frame torestrict an inclination range of the back frame.